Ski-catamaran boat



Jan. 25, 1966 Filed Oct. 9, 1964 A. M. COMPTON SKICATAMARAN BOAT 2 Sheets-Sheet l INVENTOR.

flrf/rur M Cam afar Vial-u Jan. 25, 1966 A. M. COMPTON 3,230,918

SKI-CATAMARAN BOAT Filed Oct. 9, 1964 2 Sheets-Sheet 2 INVENTOR. 54 4 1%40 M Campfax? ha '4 TOENEVS.

United States Patent f 3,230,918 SKI-CATAMARAN BOAT Arthur M. Compton, 1525 N. Withers Road, Liberty, Mo.

Filed Oct. 9, 1964, Ser. No. 402,801 9 Claims. (Cl. 11466.5)

This invention relates to improvements in boat design and refers more particularly to improvements in a catamaran and ski combination type boat design.

Rigid catamaran type boat hull constructions where paired floats are rigidly connected to the hull are known to the art. Thus Sundstedt D. 160,031 issued September 5,1950; Babcock 2,666,406 issued January 19, 1954 and Hulett 2,704,529 issued March 22, 1955. Additionally, various hydrofoil and ski type devices have been provided for use in conjunction with conventional boat hulls, Lambert 538,527 issued April 30, 1895; Reeve Re. 12,791 issued May 12, 1908; Prosser 1,075,726 issued October 4,

1913 and Waller 1,835,618 issued December 8, 1931.

These patents show the skis and/0r hydrofoils variously adjustable with respect to their hull mounting or con- :type boat wherein the floats are mounted for up and down ,and pivoting resiliency with respect to the hull.

Another object of the invention is to provide a skicatamaran boat having exceptional stopped and lowspeed stability-whereby to permit ready, easy and safe mounting and entry of the boat from a dock or the like.

' Another object of the invention is to provide a skicatamaran type boat construction which has exceptional high-speed stability.

Another object of the invention is to provide a skicatam'aran type boat which has the advantages of the wide track stability of the catamaran type boat, the advantages of low drag associated with skis, both coupled with exceptional turning capacities and maneuverability.

Another object of the invention is to provide a skicatamaran type boat which minimizes wave shock and bounce and has great longitudinal and lateral stability.

Another object of the invention is to provide a ski- ..catamaran type boat having exceptional stability over a wide range of speed.

Another object of the invention is to provide a unique suspension arrangement and system which provides limited vertical and lateral resilience for each float or 'float-ski and, additionally, limited fore and aft resilience through the same type mounting.

Another object of the invention is to provide a simple, relatively cheap, yet strong, long lived catamaran float type mounting for a boat hull, all parts of the suspension readily available for inspection, repair or replacement, the mounting of minimum air and drag resistance.

Another object of the invention is to provide a skicatamaran type boat which has a float suspension system in forward motion which resembles and has the advantages of automobile stability, namely, wide track, fourpoint support on the water surface.

Another object of the invention is to provide a skicatamaran structure or catamaran float structure and mounting therefor which may be readily applied to sub stantially any boat hull with a minimum of cost and a 3,239,918" Patented Jan. 25, 1966 'ice In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, an embodiment of the invention is shown and, in the various views, like numerals are employed to indicate like parts.

FIG. 1 is a top plan view of a boat hull mounting the subject ski-catamaran float construction and mounting therefor.

FIG. 2 is a side view of the construction of FIG. 1.

FIG. 3 is a bottom plan view of the construction of FIGS. 1 and 2.

FIG. 4 is a still water stopped rear view of the boat of FIGS. 1-3 showing details of the steering apparatus.

FIG. 5 is a view of a first stage of a turn of the subject boat construction with the boat moving away from the observer and beginning to turn from left to right in the view, the view showing the combined action of the rudders and floats in turning.

FIG. 6 is an enlarged side detail of the float and rudder connections to the hull.

FIG. 7 is a view taken along the line 7-7 of FIG. 6 in the direction of the arrows.

FIG. 8 is a view taken along the line 8-8 of FIG. 6 in the direction of the arrows.

FIG. 9 is a fragmentary end view of an alternate floathull connection.

FIG. 10 is a side detail of an alternate ski mount construction.

Referring to the drawings and particularly to FIGS. 13, inclusive, at 20 is generally designated a boat hull of relatively conventional type. Hull 20 has prow 21 beveled downwardly to the rear,.port side 22, starboard side 23 and stern or rear end bulkhead 24, the latter preferably vertical. The underside of the hull 25 is preferably substantially flat, as illustrated, except for a forward beveled portion 25a grading into beveled prow 21. Upper front deck 26 sealingly engages prow 21 and sides 22 and 23 and has transverse, transparent windshield 27 of conventional sort attached thereto in conventional manner with side portions 28 and 29 thereof to port and starboard, respectively. Hull top deck seat openings 30 and 31 are separated by intermediate hull and deck portion 32 and contain conventional cushioned seats 33 and 34 therein, the later having cushioned backs 33a and 34a connected thereto in conventional manner. Various power and steering controls of conventional type including steering wheel 35 are mounted in the front of seat opening 30 in conventional manner and will not be described. Rear deck 36 extends rearwardly of rear seat opening 31 to connect with stern bulkhead 24.

While internal power sources, such as one or more conventional inboard motors of any desired suitable type may be employed, the power source shown here is a conventional outboard motor,. generally designated 37. Motor 37 is mounted by bracket 38 on U-f-rame 39, the latter carried on stem bulkhead 24. Steering handle 40 pivots motor 37 on bracket 38. In the event that it is desired to rigidly and nonpivotally attach motor 37 onto rear bulkhead 24 and frame 39, the rudder means provided will steer the boat as to be described. Low speed steering of the boat may be accomplished either by hand pivoting of outboard motor 37 around its hull connection, in entirely conventional manner or, alternatively, the outboard mot-or may be linked to the float rudders shown, in conventional manner not illustrated, for simultaneous turning. For high speed steering, the rudder-float steering means is preferably solely employed whereby any suitable conventional means for fixing the position of the motor 37 re the hull may be employed.

The means and manner of mounting each of the floats with respect to the hull will now be described. Only one such connection will be described as all such are identical. Elongate angle members having a horizontal upper flange 41 and an angled downward hull connecting portion 42 (see FIG. 7) are fixed to each side of the hull and extend from rear bulkhead 24 forwardly to approximately the front end of seat opening 30. Support beam means for the floats are rigidly connected to horizontal flange 41 and comprise horizontal flange 43, vertical flange 44 and downwardly and inwardly directed flange 45, the latter three flanges rigidly connected together by web 46. An elongate extension 47 of flange 45 runs under the hull connecting the structural supports for the floats. Forward bracing web 48 (FIG. 6) also connects to horizontal flange 41 by bolts 49. The structural supports for the floats are four in number, two on each side of the hull at corresponding positions on the hull. All parts of said supports are numbered the same as they are identical in each of the four positions.

The floats themselves are generally designated 50 for the starboard float and 51 for the port float. Float 50 has elongate top wall 50a, elongate bottom wall 50b and elongate upwardly and inwardly angled side walls 500 and 50d, these walls connected in sealing fashion along the lengths thereof whereby to provide a generally watertight construction. Intermediate bulkheads 50c, 50 and 50g are provided as seen in FIG. 6 whereby to define sealed chambers 5011 and 50i on each side of unsealed float chamber 50 Like bulkheads are provided forward at the other float connection from the hull to float 50 whereby each unsealed chamber at a float connection is sandwiched be tween two sealed float chambers. The sealed float chambers may be filled with blocks of or loose aggregrates of cellular plastic material such as styrofoam which will aid in excluding water, provide permanent buoyancy, rigidify the floats, retain buoyancy if the float walls are breached, and the like.

The float mounting connections to the hull comprise, as seen in FIGS. 6, 7 and 8 (comprising the rearmost connection 'on the starboard side of the hull of float 50) an elongate rigid rod or shaft 52 connected to the underside of flange 45 by welding or other suitable method and extending laterally and substantially horizontally through opening 53 in wall 50d of float 50 and thus into nonseal'e'd float chamber 50 Alternatively, shaft 52 may be a relatively resilient leaf spring connected at one end to hull 20 and at the other to shaft 62. Shaft mounting wall or panel 54 connects at its lower edge to float lower wall 50b and at its upper end to bulkhead 50e by angled panel 54a. Shaft 55, externally threaded at its forward end receives nut 56 thereon on the forward side of shaft mounting wall 54, extends through opening 57 through wall 54 and is welded or otherwise fixedly attached to plate 58 on the aft side of wall 54. Fixed to the aft face of plate 58 by plastic'or rubber-metal welding or bonding process of conventional type is a resilient cylindrical rubber or other resilient plastic material block or spring designated generally 59. Block 59 is likewise welded or fixedly attached as described to plate 60, same mounting externally threaded shaft 61 on the aft face thereof, shaft 61 being received in threaded fashion in internally threaded opening 62 in rod or shaft 52. It may be seen that float 50 is thus pivotally or rotatably mounted around its longitudinal axis (yet toward the float outer wall) with respect to rod or shaft 52 by the pivotal or rotational mountings of shafts 61 and 55 in shaft 52 and wall 54, respectively. Rubber or resilient composition'block 59 gives fore and aft, up and down and in and out resilient mounting to the float with respect to the hull. Since there are four such mountings at the four float suspension points, two on each side of the hull, there are four points of resilience and four points of axial rotatability, two to each float. The hullfloat structural connection may be a low, essentially horizontal beam member as at 52, an angled connection (say,

at 45 from horizontal) from further up the side of the hull or, alternatively, an essentially vertical beam connection from an overhang above the float. The essential is the hull-float connection via end shaft 61 of resilient block 5?. The latter two alternatives may be preferable from the point of view of drag.

Alternatively beam 52-, in horizontal, angled or vertical orientation in hull-float connection may comprise an elongate metal leaf spring with a coil or wrap around end mak ing the connection at its extremity with plate 58. This is seen in the fragmentary view of FIG. 9 where 52 isthe body of the leaf spring, of resilient steel, 52a is the coil'e'nd thereof, 62 is a bolt or shaft analogous to shaft 62 of FIG. 8, the latter welded or otherwise attached to 58 which corresponds to plate 58, This alternative gives the up and down resiliency, the pitching resiliency and the pivotal same of the earlier figures.

The side walls of floats 5t) and 51 may extend downwardly past lower wall 50b whereby to provide vertical ski mounting flanges therebelow. Mounted on these flanges by rods or pins 63 are angle members 64 and 65 (FIG. 5) which carry on the lower flanges thereof skis 66, same having upwardly angled outer sides 67. Skis 66 may be of various shapes in transverse section, such as, for example, a V-shape, which is of use in rougher water and also aids vertical stabilization. Pins 63 are two in number (FIG. 6) whereby to provide rigid mounting of said ski re said floats. Stabilizing downwardly extending flanges 68 may be employed with the aft ones of skis 66, if desired. Such ski mounting is duplicated once forwardly of the mounting just described on the float 50, see FIGS. 2 and 3, and twice on float 51 and thus will not be described again. The hull-float connections as by beam 52 engaging shaft 61 on resilient member 59 are preferably separated sufiiciently along the length of the hull and floats that there is not excessive length of float forwardly of the front con nection and rearwardly of the rear connection. Substantially equal distances are preferred. This avoids excessive vertical working of the ski ends re the hull. The longitudinal positions of the skis, as best seen in FIGS. 2 and 3, are preferably substantially opposite of or forward of the forward hull connection and substantially opposite of or rearward of the rearward hull connection;

Turning to the rudder mechanism, best seen in FIGS. 1, 4, 5 and 6, shaft 69 extends sealingly yet rotatably through a bearing lined hole in rear bulkhead 24, mounting pulley 70 on one end thereof and rectangular plate 71 on the other end thereof outside of bulkhead 24 and inside of motor carrying U-frame 39. Elongate rigid rods 72 and 73 connect from ball joints 74 and 75 on the upper side of plate 71 to ball joints 74a and75a, the latter each connected to shafts or pins rigidly fixed to the top inboard wall portions of floats 50 and 51. A second set of elongate rigid rods 76 and 77 communicate from ball joints 78 and 79 on the lower edge of plate 71 out to steering knuckles 80 and 81 (only 80 seen in FIG. 6), the latter connecting via short shaft 82 to encircling connection 83 atop rudder shaft 84. Shaft 84 is received in vertical bearing 85 and mounts rudder 86 on the lower end thereof, which end extends through the lower wall 50b of the float 50.

FIG. 10 shows an alternative ski and float arrangement where the float is replaced by an elongate structural member such as a beam or hollow pipe 90 which may be: tapped and internally threaded as at 91 at the ends thereof (here the rear end) to receive the forward externally threaded shaft 92 of a spring means which includes front plate 93, resilient block 94, rear plate 95- and rear shaft 96. A hull beam 97 connection is made to the latter. Ski 98 is connected to pipe 90 by members. 99 and 100. In this option, all flotation is accomplished by the hull. Steering is accomplished by rudders 101 pivoted on shafts 102, the latter received in bearings 103 fixed to the ski upper surfaces with linkage connection to shaft 102, as previously described.

Referring back to FIG. 1, steering cable 87 is led around side pulleys 88 and 89, encircles main steering pulley 70 centrally of rear bulkhead 24 and is connected forwardly to the shaft 35a of steering wheel 35. Thus rotation of steering wheel 35 in clockwise or counterclockwise direction will operate to pull cable 87 in one direction or the other, thus revolving the pulley 70 in clockwise or counterclockwise direction thereby acting on shaft 69 and tilting plate 71 clockwise or counterclockwise in the manner seen in FIG. 5. Alternatively, a conventional push rod steering connection may be substituted. Clockwise tilting or rotation of plate 71 as seen in FIG. 5 pulls the upper portion of float 51 in a counterclockwise direction around the float mounting pivot, while rod 72 pushes the upper portion of float 50 in like clockwise direction around the pivotal mountings of shafts 61 and 55 as seen in FIG. 6. The lower portion of plate 71 being moved in the manner seen operates to tilt the rudder 86 on float 50 and its like counterpart on float 51 in counterclockwise direction (seen from above) around the respective mounting shafts whereby to aid in the turning action.

Thus, to turn the boat to the right or starboard as seen in the view of FIG. 5, wheel 35 is turned clockwise, whereby to cant plate 71 in clockwise direction, thereby moving the pontoon or float arm 72 outwardly and like arm 73 inwardly whereby to cant or rotate the top portion of each float (in the view of FIG. 5) in clockwise direction around their pivotal mountings. The rudders in each case, under the impetus of arms 76 and 77 acting through linkages previously described, when looking down from above in FIG. 6, will move counterclockwise around their mounting shafts.

To turn the boat to the left, the opposite counterclockwise turning action of wheel 35 will cause opposite actions of the various parts described, canting the pontoons or floats in the other direction and moving the rudders around their mounting shafts in the opposite direction. It is possible to couple the outboard motor, by suitable conventional cable or push r-od connections, into the turning system as described, but such is not necessary.

Thus it may be seen that hull 20 is substantially supported, preferably, on the water by the two floats 50 and 51. The relative flotation of the floats and hull may be variable, the floats optionally sufliciently buoyant to float the hull free of the water, but not necessarily. The still water loaded position is seen in FIG. 4. Wide track stability is provided as clearly evident from FIGS. 1, 3, 4 and 5. Downward thrust, or upward thrust on any one float, or both floats, or the hull itself with respect to the floats, is cushioned by resilience in the rubber or other resilient material block 59. Each float is optimally supported at two points in the manner of the four point suspension of an automobile and each float rides on two skis, at speed, to further this analogy. Each float may rotate around the longitudinal axis of the rubber spring mountings thereof, as previously described, the central positioning of plate 71 with the rod connections to the inner tops of the floats and the normal orientation of the flat bottoms of the floats with respect to the water surface generally serving to keep the floats with the bottoms level with respect to the hull save when the turning action is initiated. Likewise, the downward extension of the rudders into the water tends to maintain the floats in the position seen in FIG. 4 save when turning action is initiated. The skis may be omitted from the floats, if desired, but are much preferred for high speed planing action. The floats in such case (or, indeed, in any case) may be V-b-ottomed to a greater or lesser degree. This may be preferable for rough water usage and also aids in stabilization.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will'be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is 'to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A boat construction comprising, in combination, a boat hull having front and rear ends and elongate sides thereon, a pair of elongate ski mounting members positioned adjacent the sides of the hull, outboard of the sides thereof and extending parallel to the longitudinal axis of the hull, a pair of forwardly inclined planing ski members mounted on the underside of each ski mounting member and longitudinally spaced from one another, paired means for pivotally and resiliently mounting each vsaid elongate mounting member on the hull from two longitudinally displaced points thereon, said latter means comprising a block of resilient material having front and rear ends, a first shaft pivotally fixed to the ski mounting member and extending longitudinally of the longitudinal axis thereof and fixed at one end to one end of said resilient block, a beam member communicating from the hull to adjacent the other end of the resilient block, and a second shaft fixed at one end thereof to the other end of the resilient block and pivotally connected to the beam member at the other end thereof. 7

2. A boat construction as in claim 1 including pivotable rudder means mounted at the rear end of each of the rearmost ski members.

3. A boat construction as in claim 1 wherein the pivotal connection to the hull beam member comprises external threading on the shaft engaging an internally threaded passage in the hull beam. member.

4. A boat construction comprising, in combination, a boat hull having front and rear ends and elongate sides thereon, a pair of elongate floats positioned adjacent the sides of the hull, outboard of said sides and extending parallel to the longitudinal axis of the hull, paired means for resiliently and pivotally mounting each said float on the hull from two longitudinally displaced points thereon, each said latter means comprising, a block of resilient material having front and rear ends, a first shaft pivotally fixed to the float member and extending longitudinally of the longitudinal axis thereof and fixed at one end to one end of said resilient block, a beam member communicating from the hull to adjacent the other end of the resilient block, and a second shaft fixed at one end thereof to the other end of the resilient block and pivotally connected to the beam member at the other end thereof.

5. A boat construction as in claim 4 wherein the pivotal connection to the hull beam member comprises external threading on the shaft engaging an internally threaded passage in the hull beam member.

6. A boat construction comprising, in combination, a boat hull having front and rear ends and elongate sides thereon, a pair of elongate floats positioned adjacent the sides of the hull, outboard of said sides and extending parallel to the longitudinal axis of the hull, paired means for resiliently and pivotally mounting each said float on the hull from two longitudinally displaced points thereon, each said latter means comprising a beam member connecting the hull and the float at the ends thereof, the float connection both pivotal around the longitudinal axis of the float and resilient at the point of connection with the hull beam member, a steering connection comprising a rectangular plate pivotally mounted at its center at the rear end of the hull and normally extending vertically and in a plane transverse to the longitudinal axis of the hull, an upper rod steering linkage communicating from each upper corner of the plate to the inboard top of the adjacent fioat,'a lower rod steering linkage communicating from each lower corner of the plate to an outboard lower interior connection on the adjacent float, and means for rotating said plate around the central pivotal mounting in two directions.

7. A boat construction as in claim '6 wherein said lower rod steering linkages communicate to vertical pivotal connections to rudders mounted on the underside of said floats.

8. A boat construction comprising-in combination, a boat hull having front and rear ends and elongate sides thereon, a pair of elongate floats positioned adjacent the sides of the hull, outboard of said sides and extending parallel to the longitudinal axis of the .hull, paired means for resiliently and pivotally mounting each said float on the hull from two longitudinally displaced points thereon,

each said latter means comprising a beam member connecting the hull and the float at the ends thereof, the float connection both pivotal around the longitudinal axis of the float and resilient at the point of connection withsthe .hull beam member, and a pair of'forwardly inclined planing ski members mounted on the underside of each float and longitudinally displaced from one another, the ski members on each float mounted rearwardly and forwardly of-the rearward and forward-hull-float connections, respectively.

9. A boat construction compr1sing,-in combination, a boatthull having front andtre'ar ends and elongate sides thereon, aipair of elongate floats positionedadjacent the sides of the vhull, outboard of said sides and extending parallel to the longitudinal axis of the hull, paired means for resiliently and pivotally mounting each said float on the hull from two longitudinally displacedpoints thereon and two longitudinally displaced relatively low outboard positions in the floatsthemse'lves, said latter means comprising each a'beam member connecting the hull and the float at the ends thereof, the float connection both pivotal around'the longitudinal axis of the float and'resilient at the point or connection with the hull beam member, a steering-connection comprising a rectangular plate piv otally mounted atitscenterat the rear end of the hull References Cited by the Examiner UNITED STATES PATENTS 2,255,046 9/1941 rDiehl '11466;5 '2,344;6 19 3/1944 Lake 1.... i1 1466.5 2,5 84,1 22 2/1952 'Gilmore 1 14-7665 3,1 16,708 1/ 1964 :Gatdhouse ;1 -1' l+-.- 66.5

MILTON PBUCHLER, :Primary Examiner.

FERGUS S. "MIDDLETON, Examiner. 

1. A BOAT CONSTRUCTION COMPRISING, IN COMBINATION, A BOAT HULL HAVING FRONT AND REAR ENDS AND ELONGATE SIDES THEREON, A PAIR OF ELONGATE SKI MOUNTING MEMBERS POSITIONED ADJACENT THE SIDES OF THE HULL, OUTBOARD OF THE SIDES THEREOF AND EXTENDING PARALLEL TO THE LONGITUDINAL AXIS OF THE HULL, A PAIR OF FORWARDLY INCLINED PLANING SKI MEMBERS MOUNTED ON THE UNDERSIDE OF EACH SKI MOUNTING MEMBER AND LONGITUDINALLY SPACED FROM ONE ANOTHER, PAIRED MEANS FOR PIVOTALLY AND RESILIENTLY MOUNTING EACH SAID ELONGATE MOUNTING MEMBER ON THE HULL FROM TWO LONGITUDINALLY DISPLACED POINTS THEREON, SAID LATTER MEANS COMPRISING A BLOCK OF RESILIENT MATERIAL HAVING FRONT AND REAR ENDS, A FIRST SHAFT PIVOTING FIXED TO THE SKI MOUNTING MEMBER AND EXTENDING LONGITUDINALLY OF THE LONGITUDINAL AXIS THEREOF AND FIXED AT ONE END TO ONE END OF SAID RESILIENT BLOCK, A BEAM MEMBER COMMUNICATING FROM THE HULL TO ADJACENT THE OTHER END OF THE RESILIENT BLOCK, AND A SECOND SHAFT FIXED AT ONE END THEREOF TO THE OTHER END OF THE RESILIENT BLOCK AND PIVOTALLY CONNECTED TO THE BEAM MEMBER AT THE OTHER END THEREOF. 